Table 1.

Key features of reticular fiber and fibrotic networks

	Reticular fiber network	Fibrotic network
Physical characteristics
Tissue gaps	15–20 μm [7, 36]	<5 μm [7, 19]
Disposition of matrix fibers	In conduits, ensheathed by FRC [35]	Linear and parallel [7, 22, 40]
Phenotype of fibroblasts	Among many genes, FRC express αSMA, gp38, CCL19, CCL21, IL-7 [33]	Among many genes, fibroblasts found in fibrotic networks express αSMA, PDGF receptor-β, CXCR4, FAP, CXCL12, caveolin-1, LOX [46]
Presence of T cells	Numerous T cells filling gaps between fibers [36]	Few T cells, very elongated along ECM fibers [7]
Tissue localization	Secondary and tertiary lymphoid organs (chronically inflamed tissues, solid tumors) [30]	Wounded tissues, fibrosis, solid tumors [25]
Effects on T cells	Promotes chemokine-dependent migration, facilitating encounter with DC [100]	In tumors, prevents T cells from contacting malignant cells [7]